Support lists of values in attribute comparisons

Allows things like "where operatingsystem in RedHat, CentOS"  Previously
you had to use a regex like "where operatingsystem =~ RedHat|CentOS"
which is less precise and can be harder to read.

Closes #7
Merge pull request #28 from poblahblahblah/master

allowing ruby to compile and serve assets in production
Docker config for a demo etch server
Fix overlooked commands.xml ref to support yaml too
Switch to mysql2 gem

Seems to be the currently supported mysql client gem.
Add comment about how to build docker image
Remove dhparams, seems no longer necessary
Clean up client rakefile and VERSION setting
adding colors to the text output during an etch run